Wireless visitor / Customer ding-dong door chime Entry Alert / Entrance Alarm with motion sensorproduct :This product used advanced manufacturing technology. It has body sensing, high performance, energy-saving functions. It is without inadvertently touching or interference. And monitoring of human movement with in certain scope.It is very convenient for office, home, shop, factory and other places. With the Double-sided adhesive sticker, you can stick the door bell anywhere you want, or you can use the screws to fast the door bell on the wall, wood board, aluminum board etc. Feather : model: 5301Color: White100% Brand NewVolume is adjustable.Alarm Sound: 75~95 decibels16 kinds of melody musicBattery: 3 AAA / 1.5V batteries ( batteries are not included )Effective Alarming Detecting Distance: Approx. 2~8 metersDC : 9V (Can connect with a DC adapter wall charger directlyPower Switch: 10 seconds delay Effective Angle ：Left and right: 110°Up and down: 45° package：1x door chime